Tuesday, 27 June 2017

Limits to Church Growth 4

In three previous blogs I have looked at congregational
growth being limited by:

I.Demand
from society [1];

II.Supply
by the church [1];

III.Lack
of enthusiasts [2];

IV.Inadequate
resource production [3].

When congregational growth stalls and appears to hit a limit,
the obvious question is to ask “why?”. In particular, has growth ended because
of factors within the church, or factors in society? If there are no internal
limits to growth then society will always eventually hinder growth, limit (I)
above. However churches often cause their own growth barriers, not evangelising
enough, (II); have enthusiasts, the evangelisers, who cease to be effective,
(III); or not generating enough resources in the church to attract, disciple
and retain people, (IV).

Church congregations are a mixture of people, some are
enthusiasts, wanting to reach people and see them converted. However some are
inactive in conversion, preferring to spend their time on other aspects of
church life, worship, socials, good works and the like. The balance of people
in the church determines its culture. Thus I will put forward the hypothesis:

The balance of enthusiasts and inactive believers in
the church determines the evangelistic effectiveness of the church.

I will call this effectiveness the church’s evangelistic purity, and propose the conjecture:

Falling evangelistic purity will limit the
congregation’s growth, regardless of the size of society.

The Model

The model to represent
this situation is given in figure 1. People are converted to church from
outside. The cloud in the left hand of the diagram represents and unlimited
supply of potential converts [4]. The reinforcing loop R1 captures the action of the enthusiasts, the more enthusiasts the
more converted, thus even more enthusiasts. I have assumed all new converts
become enthusiasts first. Enthusiasts do not stay active in evangelism
indefinitely, thus they become inactive after a fixed duration, balancing loop B1.

Figure 1: Evangelistic purity model of church growth

Following the hypothesis, the conversion rate for each
enthusiast depends on the evangelistic purity of the church. If the number of
enthusiasts increases then the evangelistic purity of the church also
increases. This reinforces the growth of enthusiasts, R2. However the more inactive believers the lower the evangelistic
purity; a balancing loop resisting the growth of enthusiasts B2. If B2 is large enough then church growth will stop.

Simulation

A simulation of the model, for a given conversion rate,
duration enthusiast, and ratio of enthusiasts to inactive in the church, is
given in figure 2 [5]. Church numbers are the sum of the enthusiasts and the
inactive believers.

Figure 2: Falling evangelistic purity results in a limit to church growth

A church of 30 people grows rapidly over 40 years, but is
limited to just over 200 people as its evangelistic purity has fallen, figure 2.
This limit is reached even though the pool of potential converts is infinite.
It is a purely church induced limit, not affected by society. Looking at the two types of believers,
it can be seen that although the number of enthusiasts rises, their growth
eventually slows as they become increasingly ineffective in a church becoming
dominated by believers with no interest in evangelism, figure 3. Enthusiast
numbers peak and afterwards fall away.

Analysing the cause of the changes in enthusiast numbers
shows that it is the impact of the loop B2
that causes their numbers to fall and eventually halts church growth. Impact is
a measure of the extent to which a feedback loop influences the curvature of
the graph [6]. Figure 4 shows the regions of loop dominance on the enthusiasts.

Figure 4: Periods of loop dominance on enthusiast numbers

Enthusiast growth initially accelerates due to R1, their rising numbers, and R2, the influence of the enthusiasts on
evangelistic purity, figure 4, first phase. The growth slows due to the
generation of inactive believers, B1,
and their negative effect on evangelistic purity, B2, second phase. Loop B2
becomes so powerful it causes the number of enthusiasts to change from growth
to decline as conversions fall below the loss of enthusiasts. This is the third
phase.

Thus the conjecture is
demonstrated, falling church purity limits church growth, because the negative
effect of inactive believers limits the generation of enthusiasts.

Tipping Point

So what can be done to remove this barrier to growth? There
are three possible strategies:

1.Increase the effectiveness of the enthusiasts;

2.Increase the duration new converts remain
enthusiastic;

3.Have a church that has a greater balance of
enthusiasts to inactive.

Applying any of these three strategies raises the limit to
the congregation’s growth, due to a larger generation of enthusiasts. Figures 5
and 6 show the effect of increasing the initial purity of the church, the ratio
of enthusiasts to inactive. Purity 1
is the lowest; Purity 5 the highest.
Thus the more evangelistically pure churches are able to reach a higher limit
to growth than the impure ones.

Figure 5: Effect of increasing initial church purity on church growth

Figure 5: Effect of increasing initial church purity on growth of enthusiasts

There comes a point if the purity is increased further, church
growth continues indefinitely, curve Purity
5,figure 5, because enthusiasts
continue to be generated, figure 6. Thus a sufficiently pure congregation can
remove this barrier to church growth, and concentrate on the other barriers
that come into play, not included in this model. It is good to know some growth
barriers can be removed.

One way to raise church purity is to allow the inactive to
leave. It sounds counter-intuitive, but if church leaving increases, church
growth increases, as long as it is the evangelistically inactive that leave.
This is an example of Kelley’s hypothesis that a stricter church is stronger
and thus more likely to grow [7].

The principle of evangelistic purity encouraging growth can
apply across all churchmanships, not just conservative or evangelical ones, as purity
refers to participation in the mission and recruitment to the church, rather
than theology as such. It may be possible to show that certain theologies are
more likely to encourage evangelistic purity, particularly ones that see the
need for personal salvation. But that takes us beyond this simple model, which
shows that having enough people in the church committed to evangelism can
remove a barrier to church growth.

References & Notes

[1] Limits to Church Growth – Part 1. Lack of
Supply & Lack of Demand.

[5] It is normal to use computer simulation to produce
results of system dynamics model, though not always essential. The results of
the evangelistic purity model can all be proved mathematically. In this blog
the graphs were produced By the Stella Architect software, ISEE systems, https://www.iseesystems.com/

[6] The concept of loop impact is related to the concept of
force in Newtonian mechanics. See: